Method of producing carbonic acid esters and a catalyst therefore

ABSTRACT

Carbonic acid esters are important compounds as a gasoline extender, an octane number improver, an organic solvent and a reacting agent in place of phosgene for production of isocyanates, polycarbonates and various intermediates of agricultural chemicals and pharmaceuticals. 
     According to the present invention, carbonic acid esters can be prepared by reacting an alcohol with carbon monoxide and oxygen in the presence of a catalyst comprising a copper halide and a tertiary organophosphorus compound having phenyl group or alkyl group.

FIELD OF THE INVENTION

Carbonic acid esters are important compounds as a gasoline extender, anoctane number improver, an organic solvent and a reacting agent in placeof phosgene for production of isocyanates, polycarbonates and variousintermediates of agricultural chemicals and pharmaceuticals.

The present invention relates to a method of producing carbonic acidesters by oxidation-carbonylation of alcohols, and to a catalyst forproducing carbonic acid esters.

DESCRIPTION OF THE PRIOR ART

As to methods of producing carbonic acid esters from alcohols, carbonmonoxide and oxygen, liquid phase reaction using copper chloride as acatalyst is known. To improve the liquid phase method, numerous patentsemploying copper system catalysts or palladium system catalysts havebeen disclosed.

For example, Japanese Patent Provisional Publication No. Sho50.40528(1975) discloses a method using an alcoholic (methanolic)solution of a catalyst system comprising copper chloride or copperbromide, and triarylphosphineoxide or a salt of organic phosphorusacids, phosphoric acids or phosphonic acids.

Furthermore, mentions are made on such methods as a method (JapanesePatent Provisional Publication No. Sho 54.24827(1979)) of using acatalyst comprising a cuprous halide and an alkali metal or an alkalineearth metal halide, a method (Japanese Patent Provisional PublicationNo. Sho 60.75447(1985)) of using a catalyst comprising palladium, aheteropolyacid and a nitrogen compound selected from a group consistingof nitric acid, nitrous acid esters and nitrogen oxide, and a method(Japanese Patent Provisional Publication No. Sho 62.81356(1987)) ofusing a catalyst system containing a hydrocarboxy copper halide, animidazole compound, a pyridine compound or a cyclic amide.

However in the liquid phase method, there are such defects as (1) theactivity of catalyst lowers remarkably due to water and carbon dioxideformed during the reaction; (2) materials for reaction equipments arecorroded by dissolved state halides used as the catalyst, and (3)difficulties in separating reaction products and dissolved catalystsfrom effluent of reactors.

Japanese Patent Provisional Publication No. Sho 60.75447(1985) proposesemployment of a carrier like active carbon, silica gel, alumina, etc.for metallic palladium or a palladium compound which constitutes one ofcomponents of the catalyst, however, the above mentioned defects are notalways overcome.

As a method of solving these defects, researches on synthesis ofcarbonic acid esters by gas phase reaction have been conducted, andInternational Application Publication W087/07601 discloses a method ofproducing carbonic acid esters by gas phase reaction of an alcohol,carbon monoxide and oxygen in the presence of a catalyst carrying copperhalides on a carrier (active carbon, alumina, titania, silica, etc.).

However, conventional catalyst systems are low in the activity or arerequired to be operated under severe reaction conditions in order toimprove the yield.

The object of the present invention is to provide a method of producingcarbonic acid esters from alcohol, carbon monoxide and oxygen, which iscapable of maintaining an enhanced activity for a long period of time,and also to provide a catalyst for the production.

SUMMARY OF THE INVENTION

A method of producing carbonic acid esters according to the presentinvention is characterized by reacting an alcohol with carbon monoxideand oxygen in the presence of a catalyst containing a copper halide anda tertiary organophosphorus compound having phenyl group or alkyl group.

And, a catalyst for producing carbonic acid esters according to thepresent invention is characterized by comprising a copper halide and atertiary organophosphorus compound having phenyl group or alkyl group.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As for copper halides which are one of active ingredients of thecatalyst, copper chloride, copper bromide and copper iodide arementioned, and copper chloride may be used usually due to the cost andavailability.

As for tertiary organophosphorus compounds having phenyl group or alkylgroup, alkylarylphosphines like triphenylphosphine, triphenylphosphiteand dimethylphenylphosphine, trialkylphosphites like trimethylphosphiteand triethylphosphite, and trialkylphosphates like triethylphosphate andtrimethylphosphate are mentioned.

The active ingredients may exist either in a form of a mixture of acopper halide and a tertiary organophosphorus compound having phenylgroup or alkyl group, or in a form of a copper complex prepared byreacting a copper halide with a tertiary organophosphorus compoundhaving phenyl group or alkyl group.

The catalyst comprising a copper halide and a tertiary organophosphoruscompound having phenyl group or alkyl group may either be carried or notcarried on a porous carrier, however, that of carried on a porouscarrier exhibits a higher yield of carbonic acid esters per unit weightof the active ingredient comprising a copper halide and a tertiaryorganophosphorus compound.

As for porous carriers, those having surface areas of 30 m² /g or aboveare preferred, and active carbon, titanium oxide, zirconium oxide,niobium oxide, magnesium oxide, silica and alumina are exemplified, andactive carbon is the most preferred.

A copper halide and the above-mentioned tertiary organophosphoruscompound may be carried on a carrier with a solvent at around theboiling point of the solvent. For example, it is conducted with ethanolsolvent at 70°-80° C., and preferably under an inert gas (nitrogen,argon or helium) stream saturated with ethanol.

As a method of carrying a copper halide and a tertiary organophosphoruscompound having phenyl group and alkyl group on a carrier, such mannersare employable as the copper halide is carried firstly and then thetertiary organophosphorus compound is carried; the tertiaryorganophosphorus compound is carried firstly and then the copper halideis carried; and a copper complex prepared beforehand by reacting thecopper halide with the tertiary organophosphorus compound is carried ona carrier. For example, in an ethanol solution of a copper halide isadded a carrier so as the copper halide is carried, and then an ethanolsolution of a tertiary organophosphorus compound is added to solidifycopper halide-tertiary organophosphorus compound on the carrier. Asanother manner, an ethanol solution of a tertiary organophosphoruscompound is firstly made contact with a carrier, and then an ethanolsolution of a copper halide is made contact.

Amounts of the tertiary organophosphorus compound to be added arepreferably 0.05-0.4 mol per copper atom mol in the copper halide.

When the catalyst is carried on a carrier, contents of the copper halidein the catalyst is preferably around 2-10 wt.% per carrier as copper inthe copper halide.

After the copper halide-tertiary organophosphorus compound is fixed on acarrier, the solvent is removed. For example, removal of the solventethanol is performed by evaporation at 70°-80° C. under air or an inertgas atmosphere. In another manner, ethanol may be removed by applyingvacuum at relatively low temperatures as 40° C.

When a complex is prepared beforehand with a copper halide and atertiary organophosphorus compound, then the complex is carried on acarrier, the copper halide is dissolved in a solvent like ethanol ormethylene chloride, and to the solution is added under an inert gasatmosphere a tertiary organophosphorus compound dissolved in a solventlike ethanol or methylene chloride to cause a reaction, and then thesolvent is removed to obtain the copper complex.

The copper complex is carried on a carrier and fixed by dissolving thusobtained copper complex in such a solvent like chloroform, and thesolution is applied on various porous carriers, or the complex is fixedon a carrier by mixing physically the complex wet with a solvent like alower alcohol or in the absence of solvent, and then processing under aninert gas atmosphere (nitrogen, argon or helium) for stabilization.

As for copper complexes prepared with a copper halide and a tertiaryorganophosphorus compound, those represented by the following formulaare especially preferred;

    Cu(PPh.sub.3).sub.n X [PPh.sub.3 =P(C.sub.6 H.sub.5).sub.3 ; X=halogen; n=1, 2 or 3].

The above-mentioned copper complex can be prepared with copper halideslike cuprous chloride or cupric chloride and triphenyl phosphine. (referto examples for preparing copper complexes)

Contents of the copper complex in the catalyst are to be around 2-10wt.% per carrier as copper in the copper complex.

Catalysts with such copper complexes carried on carriers exhibit higheractivities than a copper complex by itself in the synthesis of carbonicacid esters by oxidation-carbonylation of alcohols.

As to raw material alcohols, aliphatic alcohols having 1-4 carbon atoms,alicyclic alcohols and aromatic alcohols are employable. Examplesthereof are methanol, ethanol, propylalcohol, butanol, cyclohexanol andbenzylalcohol, and primary alcohols like methanol and ethanol arepreferred.

Reaction conditions for producing carbonic acid esters from alcohols,carbon monoxide and oxygen are preferably reaction temperature of70°-200° C. and reaction pressure of from atmospheric pressure to 15kg/cm² G for the vapor phase reaction, and reaction temperature of80°-150° C. and reaction pressure of 5-30 kg/cm² G for the liquid phasereaction.

Molar ratios of carbon monoxide and oxygen to alcohols like methanol orethanol are preferably around 1.2-0.5 and 0.55-0.01 respectively (CO/O₂ratio=1/1-100/1).

The present invention will be explained concretely hereunder withexamples, but the invention never be limited by the examples.[Comparative Example 1]

A test was conducted for a known catalyst carrying copper halide on aporous carrier.

Into a 500 ml (milliliter) flask, 8.465 grams of cupric chloride (CuCl₂)and 150 ml of ethanol were charged to make a solution. Then, 50 grams ofan active carbon (surface area: 1000 m² /g; 4-16 mesh) were added to thesolution and stirred. Ethanol was evaporated on a hot bath of 70°-80° C.to obtain Catalyst B1.

For the purpose of measuring activity of Catalyst B1 for dimethylcarbonate formation, a measurement was conducted using an ordinaryatmospheric pressure fixed bed flow reactor under the following reactionconditions.

Into a stainless reactor tube having 10 mm inner diameter was packed 0.5ml of Catalyst B1, and 6 ml/hr of methanol, 67 ml/min of carbon monoxideand 34 ml/min of oxygen were introduced into the tube under a vaporphase reaction conditions of 150° C. and atmospheric pressure to measureactivity for dimethyl carbonate formation. The result is shown in Table1.

EXAMPLE 1

Catalyst A1-A7 mentioned hereunder were prepared, and their activitiesfor dimethyl carbonate formation were measured under the same conditionswith Comparative Example 1, and the results are shown in Table 1.

Catalyst Al: Into a 500 ml flask equipped with a reflux condenser werecharged 8.465 grams of cupric chloride (CuCl₂) and 150 ml of ethanol tomake a solution, and 50 grams of an active carbon (surface area: 1000 m²/g; 4-16 mesh) were added to the solution. The solution was maintainedat 70°-80 C. under a stream of nitrogen gas saturated with ethanol, anda solution prepared by dissolving 1.94 grams of triphenylphosphine asthe tertiary organophosphorus compound in 100 ml of hot ethanol waspoured slowly into the flask through the reflux condenser. The mixturewas stirred vigorously under reflux for 2 hours. After completion of thereflux, the reflux condenser was removed and ethanol was evaporated toobtain Catalyst A1.

Catalyst A2: Catalyst A2 was prepared in the same manner with CatalystA1 with the exception that 1.655 ml of triphenylphosphite was used asthe tertiary organophosphorus compound in place of triphenylphosphineused for preparation of Catalyst A1.

Catalyst A3: Catalyst A3 was prepared in the same manner with CatalystA1 with the exception that 0.754 ml of trimethylphosphite was used asthe tertiary organophosphorus compound in place of triphenylphosphineused for preparation of Catalyst A1.

Catalyst A4: Catalyst A4 was prepared in the same manner with CatalystA1 with the exception that 1.08 ml of triethylphosphite was used as thetertiary organophosphorus compound in place of triphenylphosphine usedfor preparation of Catalyst A1.

Catalyst A5: Catalyst A5 was prepared in the same manner with CatalystA1 with the exception that 1.08 ml of triethylphosphate was used as thetertiary organophosphorus compound in place of triphenylphosphine usedfor preparation of Catalyst A1.

Catalyst A6: Catalyst A6 was prepared in the same manner with CatalystA1 with the exception that 5.145 grams of triphenylphosphine was used asthe tertiary organophosphorus compound.

Catalyst A7: Catalyst A7 was prepared in the same manner with CatalystA1 with the exception that 3.175 grams of cupric chloride and 1.94 gramsof triphenylphosphine were used.

As is shown clearly by the test results in Table 1, when an alcohol isreacted in a vapor phase with carbon monoxide and oxygen in the presenceof a catalyst containing a copper halide and a tertiary organophosphoruscompound having phenyl group or alkyl group, an enhanced activity offormation and selectivity for dimethyl carbonate are observed incomparison with the case of using the known catalyst B1 (catalyst ofInternational Application Publication W087/07601) carrying only a copperhalide on a carrier.

                                      TABLE 1                                     __________________________________________________________________________    Catalyst         Mole ratio                                                                           Dimethylcarbonate Formation                           Cu    Tertiary organo-                                                                        of organo-                                                                            Activity of                                                                           Relative                                      content                                                                             phosphorus                                                                              phosphorus                                                                            formation                                                                             activity of                                                                          Selectivity                                                                         Relative                         wt. % compound  compound/Cu                                                                           mol/l - cat · h                                                              formation *1                                                                         %     selectivity                      __________________________________________________________________________                                                 *2                               B1                                                                              8   none      0       0.70    1.0    32    1.0                              A1                                                                              8   triphenylphosphine                                                                      0.12    2.01    2.9    70    2.2                              A2                                                                              8   triphenylphosphite                                                                      0.10    1.39    2.0    55    1.7                              A3                                                                              8   trimethylphosphite                                                                      0.10    1.34    1.9    65    2.0                              A4                                                                              8   triethylphosphite                                                                       0.10    1.38    2.0    62    1.9                              A5                                                                              8   triethylphosphate                                                                       0.10    1.32    1.9    62    1.9                              A6                                                                              8   triphenylphosphine                                                                      0.31    1.64    2.3    56    1.8                              A7                                                                              3   triphenylphosphine                                                                      0.31    2.09    3.0    74    2.3                              __________________________________________________________________________     *1: Activity of formation relative to 1.0 of Catalyst B1                      *2: Selectivity relative to 1.0 of Catalyst B1                           

COMPARATIVE EXAMPLE 2

Catalyst B2 (copper content 8 wt.%) was prepared in the same manner withComparative Example 1 with the exception that an alumina (surface area:150 m² /g) was used as a carrier. Its activity of formation for dimethylcarbonate measured by the same method with Comparative Example 1 was0.043 mol/1-cat·h. Its selectivity for dimethyl carbonate was 18%.

EXAMPLE 2

Catalyst A8 (copper content 8 wt.%; mole ratio of organophosphoruscompound/Cu =0.12) was prepared in the same manner with Catalyst A1 ofExample 1 with the exception that an alumina (surface area: 150 m² / g)was used as a carrier. Its activity of formation for dimethyl carbonatemeasured by the same method with Comparative Example 1 was 0.247mol/1.cat·h, which was 5.7 times of the catalyst of Comparative Example2. Its selectivity for dimethyl carbonate was 61%, which was 3.4 timesof the catalyst of Comparative Example 2.

COMPARATIVE EXAMPLE 3

Catalyst B3 (copper content 8 wt.%) was prepared in the same manner withComparative Example 1 with the exception that titanium oxide (surfacearea: 30 m² /g) was used as a carrier. Its activity of formation fordimethyl carbonate measured by the same method with Comparative Example1 was 0.040 mol/1-cat·h. Its selectivity for dimethyl carbonate was 16%.

EXAMPLE 3

Catalyst A9 (copper content 8 wt.%; mole ratio of organophosphoruscompound/Cu =0.12) was prepared in the same manner with Catalyst A1 ofExample 1 with the exception that titanium oxide (surface area: 30 m²/g) was used as a carrier. Its activity of formation for dimethylcarbonate measured by the same method with Comparative Example 1 was0.106 mol/1-cat·h, which was 2.7 times of the catalyst of ComparativeExample 3. Its selectivity for dimethyl carbonate was 43%, which was 2.7times of the catalyst of Comparative Example 3.

As is shown clearly by the above test results, when an alcohol isreacted in a vapor phase with carbon monoxide and oxygen in the presenceof a catalyst containing a copper halide and a tertiaryorganophosphorous compound having phenyl group or alkyl group, anenhanced activity of formation and selectivity for dimethyl carbonateare observed in comparison with a known catalyst composed of only acopper halide.

EXAMPLE 4

Synthesis tests for dimethyl carbonate were conducted using a highpressure fixed bed reactor. Into a stainless reactor tube having 12 mminner diameter was packed respectively 7 ml of Catalysts A10-A19mentioned below. To the tube were introduced 5 g/hr of methanol, 57.8ml/min of carbon monoxide and 3.6 ml/min of oxygen under vapor phasereaction conditions of 6 kg/cm² G and 150° C. to measure activities fordimethyl carbonate (DMC) formation. The results after 5 hours from thestart of reaction are shown in Table 2.

Catalyst A10: Into a 500 ml flask equipped with a reflux condenser werecharged 13.44 grams of cupric chloride and 150 ml of ethanol to make asolution. The solution was maintained at 70°-80C. under an inert gas(nitrogen) stream. Then, 39.35 grams of triphenylphosphine [P(C₆ H₅)₃abbreviated as PPh3]dissolved in 300 ml of ethanol were poured slowlyand stirred for 2 hours under reflux. After completion of the reflux,the reaction product washed well with hot ethanol and filtered to obtaina complex represented by a formula Cu(PPh₃)Cl as Catalyst A10.

Catalyst A12: To 3.751 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of an active carbon (surface area:1000 m² /g; 4.16 mesh) and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 250° C. for 3 hours to obtain Catalyst A11.

Catalyst A12: To 3.751 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of the active carbon used inCatalyst A11 and a small amount of ethanol as a solvent, and mixed.After drying, the mixture was treated under an inert gas stream at 300°C. for 3 hours to obtain Catalyst A12.

Catalyst A13: To 1.705 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of the active carbon used inCatalyst A11 and a small amount of ethanol as a solvent, and mixed.After drying, the mixture was treated under an inert gas stream at 250°C. for 3 hours to obtain Catalyst A13.

Catalyst A14: To 5.114 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of the active carbon used inCatalyst A11 and a small amount of ethanol as a solvent, and mixed.After drying, the mixture was treated under an inert gas stream at 250°C. for 3 hours to obtain Catalyst A14.

Catalyst A15: To 6.820 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of the active carbon used inCatalyst A11 and a small amount of ethanol as a solvent, and mixed.After drying, the mixture was treated under an inert gas stream at 250°C. for 3 hours to obtain Catalyst A15.

Catalyst A16: To 3.751 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of titanium oxide and a smallamount of ethanol as a solvent, and mixed. After drying, the mixture wasmolded and treated under an inert gas stream at 250° C. for 3 hours toobtain Catalyst A16.

Catalyst A17: To 6.252 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of zirconium oxide and a smallamount of ethanol as a solvent, and mixed. After drying, the mixture wasmolded and treated under an inert gas stream at 250° C. for 3 hours toobtain Catalyst A17.

Catalyst A18: To 6.252 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of niobium oxide and a smallamount of ethanol as a solvent, and mixed. After drying, the mixture wasmolded and treated under an inert gas stream at 250° C. for 3 hours toobtain Catalyst A18.

Catalyst A19: To 3.751 grams of a complex obtained in the same mannerwith Catalyst A10 were added 20 grams of silica and a small amount ofethanol as a solvent, and mixed. After drying, the mixture was moldedand treated under an inert gas stream at 250° C. for 3 hours to obtainCatalyst A19:

COMPARATIVE EXAMPLE 4

By using 3.175 grams of cupric chloride in Comparative Example 1 and inthe same manner with Comparative Example 1, Catalyst B4 was obtained.Its activity of formation for dimethyl carbonate was measured in thesame manner with Example 4. Result obtained after 5 hours from the startof reaction is shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                                           Yield of                                                     Amount           DMC                                        Catalyst          of       Yield   per unit                                                Content  complex  of    amount of                                             of Cu    charged  DMC   complex                                  Carrier      % *1     g        % *2  %/g                                      ______________________________________                                        B4   Active carbon                                                                             3.0      --     1.8   --                                     A10  None        --       4.1    10.7   2.6                                   A11  Active carbon                                                                             3.3      0.584  9.6   16.4                                   A12  Active carbon                                                                             3.3      0.584  9.2   15.8                                   A13  Active carbon                                                                             1.5      0.291  4.5   15.5                                   A14  Active carbon                                                                             4.5      0.753  10.6  14.1                                   A15  Active carbon                                                                             6.0      0.992  10.5  10,6                                   A16  Titanium oxide                                                                            3.3      1.026  11.4  11.1                                   A17  Zirconium   5.5      1.858  9.8    5.27                                       oxide                                                                    A18  Niobium oxide                                                                             5.5      1.858  16.6   8.93                                  A19  Silica      3.3      0.426  4.1    9.62                                  ______________________________________                                         *1: Weight ratio of Cu per carrier                                            ##STR1##                                                                 

DMC is obtained more effectively by using a catalyst containing acomplex represented by the formula Cu(PPh₃)C1 when compared with thecase using a known catalyst B4 (catalyst in International ApplicationPublication W087/07601) carrying only CuCl₂ on a carrier. Though a highyield of DMC is obtained when Catalyst A10 composed only of a complexrepresented by the formula Cu(PPh₃)Cl, however, catalysts carried oncarriers are superior from the viewpoints of yield of DMC per unitamount of the complex.

EXAMPLE 5

Synthesis tests for dimethyl carbonate were conducted with CatalystsA20-A36 mentioned below using a high pressure fixed bed reactor.

Into a stainless reactor tube having 12 mm inner diameter was packed 7ml of respective catalyst. To the tube were introduced 5 g/hr ofmethanol, 57.8 ml/min of carbon monoxide and 3.6 ml/min of oxygen undervapor phase reaction conditions of 6 kg/cm² G and 150° C. to measureactivities for dimethyl carbonate formation. Yields of dimethylcarbonate after 5 hours from the start of reaction are shown in Table 3.

Catalyst A20: Into a flask equipped with a reflux condenser were charged4.90 grams of cuprous chloride (CuCl) and 100 ml of methylene chlorideto make a solution, and the solution was maintained at around 10° C.under an inert gas (nitrogen) stream. Then, 26.2 grams oftriphenylphosphine (PPh3) dissolved in 100 ml of methylene chloride werepoured slowly into the solution and the reaction was continued underagitation for 2 hours. After the reaction was completed, the reactionproduct was washed with hot ethanol and 5% aqueous ammonia, thenfiltered to obtain a complex represented by a formula Cu(PPh₃)₂ Cl asCatalyst A20.

Catalyst A21: To 5.89 grams of the complex Cu(PPh₃)₂ Cl obtained in thesame manner with Catalyst A20 were added 20 grams of an active carbon(surface area 1000 m² /g; 4.16 mesh) and a small amount of ethanol as asolvent, and mixed. After drying, the mixture was treated under an inertgas stream at 250° C for 3 hours to obtain Catalyst A21.

Catalyst A22: To 5.89 grams of the complex Cu(PPh₃)₂ Cl obtained in thesame manner with Catalyst A20 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 330° C. for 3 hours to obtain Catalyst A22.

Catalyst A23: To 5.89 grams of the complex Cu(PPh₃)₂ Cl obtained in thesame manner with Catalyst A20 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 390° C. for 3 hours to obtain Catalyst A23.

Catalyst A24: To 9.82 grams of the complex Cu(PPh₃)₂ Cl obtained in thesame manner with Catalyst A20 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 250° C. for 3 hours to obtain Catalyst A24.

Catalyst A25: Into a flask equipped with a reflux condenser were charged4.90 grams of cuprous chloride (CuCl) and 100 ml of methylene chlorideto make a solution, and the solution was maintained at around 40° C.under an inert gas (nitrogen) stream. Then, 39.3 grams oftriphenylphosphine (PPh3) dissolved in 100 ml of methylene chloride werepoured slowly into the solution, and the reflux was continued underagitation for 2 hours. After the reflux was completed, the reactionproduct was washed with hot ethanol and 5% aqueous ammonia, thenfiltered to obtain a complex having a structure of Cu(PPh₃)₃ Cl asCatalyst A25.

Catalyst A26: To 8.36 grams of the complex Cu(PPh₃)₃ Cl obtained in thesame manner with Catalyst A25 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 330° C. for 3 hours to obtain Catalyst A26.

Catalyst A27: Into a flask equipped with a reflux condenser were charged11.2 grams of cupric bromide (CuBr₂) and 100 ml of ethanol to make asolution, and the solution was maintained at 70°-80° C. under an inertgas stream. Then, 20.0 grams of triphenylphosphine (PPh₃) dissolved in100 ml of hot ethanol were poured slowly into the solution, and refluxedfor 2 hours under agitation. After completion of the reflux, thereaction product was washed with hot ethanol, then filtered to obtain acomplex represented by a formula Cu(PPh3)Br as Catalyst A27.

Catalyst A28: To 3.83 grams of the complex Cu(PPh₃)Br obtained in thesame manner with Catalyst A27 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 330° C. for 3 hours to obtain Catalyst A28.

Catalyst A29: Into a flask equipped with a reflux condenser were charged7.00 grams of cuprous bromide (CuBr) and 100 ml of methylene chloride tomake a solution and the solution was maintained at around 10° C. underan inert gas stream. Then, 26.2 grams of triphenylphosphine (PPh₃)dissolved in 100 ml of methylene chloride were poured slowly into thesolution and the reaction was continued for 2 hours under agitation.After completion of the reaction, the reaction product was washed withhot ethanol and 5% aqueous ammonia, then filtered to obtain a complexhaving a structure of Cu(PPh₃)₂ Br as Catalyst A29.

Catalyst A30: To 6.31 grams of the complex Cu(PPh₃)₂ Br obtained in thesame manner with Catalyst A29 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 250° C. for 3 hours to obtain Catalyst A30.

Catalyst A31: To 6.31 grams of the complex Cu(PPh₃)₂ Br obtained in thesame manner with Catalyst A29 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas stream340° C. for 3 hours to obtain Catalyst A31.

Catalyst A32: To 10.5 grams of the complex Cu(PPh₃)₂ Br obtained in thesame manner with Catalyst A29 were added 20 grams of the active carbonuse in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under inert gas stream at340° C. for 3 hours to obtain Catalyst A32.

Catalyst A33: Into a flask equipped with a reflux condenser were charged7.00 grams of cuprous bromide and 100 ml of methylene chloride to make asolution, and the solution was maintained at around 40° C. under aninert gas stream. Then, 39.3 grams of triphenylphosphine (PPh₃)dissolved in 100 ml of methylene chloride were poured slowly into thesolution and the solution was refluxed for 2 hours under agitation.After completion of the reflux, the reaction product was washed with hotethanol and 5% aqueous ammonia, then filtered to obtain a complexrepresented by a formula Cu(PPh₃)₃ Br as Catalyst A33.

Catalyst A34: To 8.79 grams of the complex Cu(PPh₃)₃ Br obtained in thesame manner with Catalyst A33 were added 20 grams of the active carbonused in Catalyst A21 and a small amount of ethanol as a solvent, andmixed. After drying, the mixture was treated under an inert gas streamat 340° C. for 3 hours to obtain Catalyst A34.

Catalyst A35: Into a flask equipped with a reflux condenser were charged6.70 grams of cupric chloride, 15 grams of sodium iodide and 100 ml ofethanol to make a solution, and the solution was maintained at 70°-80°C. under an inert gas (nitrogen) stream. Then, 20 grams oftriphenylphosphine (PPh3) dissolved in 100 ml of ethanol were pouredslowly into the solution and refluxed for 2 hours under agitation. Aftercompletion of the reflux, the reaction product was washed with hotalcohol, then filtered to obtain a complex represented by a formulaCu(PPh3)I as Catalyst A35.

                                      TABLE 3                                     __________________________________________________________________________    Catalyst                                    Yield of                          Organo-               Content                                                                            Amount of        DMC per unit                      phosphorus                                                                              Carrier:    of Cu                                                                              complex charged                                                                        Yield of DMC                                                                          amount of complex                 compound  Treatment temperature                                                                     % *1 g        % *2    %/g                               __________________________________________________________________________    A20                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               None        --   4.2      1.8     0.43                              A21                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               Active carbon                                                                             3.0  0.911    4.0     4.39                                        250° C.                                                      A22                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               Active carbon                                                                             3.0  0.911    6.5     7.14                                        330° C.                                                      A23                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               Active carbon                                                                             3.0  0.911    6.0     6.59                                        390° C.                                                      A24                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               Active carbon                                                                             5.0  1.480    7.2     4.86                                        250° C.                                                      A25                                                                              Cu(PPh.sub.3).sub.3 Cl                                                               None        --   4.6      1.2     0.26                              A26                                                                              Cu(PPh.sub.3).sub.3 Cl                                                               Active carbon                                                                             3.0  1.179    5.6     4.39                                        330° C.                                                      A27                                                                              Cu(PPh.sub.3)Br                                                                      None        --   4.3      10.9    2.52                              A28                                                                              Cu(PPh.sub.3)Br                                                                      Active carbon                                                                             3.0  0.611    8.0     13.1                                        330° C.                                                      A29                                                                              Cu(PPh.sub.3).sub. 2 Br                                                              None        --   4.7      1.6     0.34                              A30                                                                              Cu(PPh.sub.3).sub.2 Br                                                               Active carbon                                                                             3.0  0.936    5.0     5.34                                        250° C.                                                      A31                                                                              Cu(PPh.sub.3).sub.2 Br                                                               Active carbon                                                                             3.0  0.936    7.5     8.01                                        340° C.                                                      A32                                                                              Cu(PPh.sub.3).sub.2 Br                                                               Active carbon                                                                             5.0  1.520    8.2     5.39                                        340° C.                                                      A33                                                                              Cu(PPh.sub.3).sub.3 Br                                                               None        --   4.9      1.2     0.24                              A34                                                                              Cu(PPh.sub.3).sub.3 Br                                                               Active carbon                                                                             3.0  1.179    4.5     3.82                                        340° C.                                                      A35                                                                              Cu(PPh.sub.3)I                                                                       None        --   4.3      2.3     0.53                              A36                                                                              Cu(PPh.sub.3)I                                                                       Active carbon                                                                             3.0  0.652    4.0     6.13                                        380° C.                                                      A37                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               TiO.sub.2 :250° C.                                                                 3.0  1.802    2.0     1.11                              A38                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               ZrO.sub.2 :250° C.                                                                 3.0  3.240    4.1     1.26                              A39                                                                              Cu(PPh.sub.3).sub.2 Cl                                                               Nb.sub.2 O.sub.5 :250° C.                                                          3.0  3.230    4.8     1.49                              __________________________________________________________________________

Catalyst A36: To 4.28 grams the complex Cu(PPh₃)I obtained in the samemanner with Catalyst A35 were added 20 grams of the active carbon usedin Catalyst A21 and a small amount of ethanol as a solvent and mixed.After drying, the mixture was treated under an inert gas stream at 380°C. for 3 hours to obtain Catalyst A36.

Catalyst A37: To 5.89 grams of the complex obtained in the same mannerwith Catalyst A20 were added 20 grams of titanium oxide and a smallamount of ethanol, and mixed. After drying, the mixture was molded andtreated under an inert gas stream at 250° C. for 3 hours to obtainCatalyst A37.

Catalyst A38: To 5.80 grams of the complex obtained in the same mannerwith Catalyst A20 were added 20 grams of zirconium oxide and a smallamount of ethanol as a solvent, and mixed. After drying, the mixture wasmolded and treated under an inert gas stream at 250° C. for 3 hours toobtain Catalyst A38.

Catalyst A39: To 5.89 grams of the complex obtained in the same mannerwith Catalyst A20 were added 20 grams of niobium oxide and a smallamount of ethanol as a solvent, and mixed. After drying, the mixture wasmolded and treated under an inert gas stream at 250° C. for 3 hours toobtain Catalyst A39.

It is noticed from Table 3 that copper complexes represented by theformula Cu(PPh₃)_(n) X [PPh₃ is P(C₆ H₅)3; X=halogen; n=1,2 or 3]areeffective for production of carbonic acid esters, and especially thatthe yield per unit amount of copper complex increases remarkably forcomplexes carried on carriers.

EXAMPLE 6

Using Catalyst A7 which carried firstly a copper chloride and thentriphenylphosphine and Catalyst A11 which carried a complex preparedbeforehand by the reaction of a copper chloride and triphenylphosphine,activities for dimethyl carbonate (DMC) formation were investigatedafter 2 hours and 40 hours from the start of vapor phase reactions bythe same method with Example 4, and the result are shown in Table 4.

                  TABLE 4                                                         ______________________________________                                        Catalyst       Yield of DME (%) *2                                            Content of Cu  2 hours after                                                                              40 hours after                                    wt. % *1       start of reaction                                                                          start of reaction                                 ______________________________________                                        A11   3.3           9.6         9.6                                           A7    3.0          12.0         3.4                                           ______________________________________                                         *1: Weight ratio of Cu per carrier                                            ##STR2##                                                                 

It is noticed that Catalyst A11 carrying on a porous carrier a complexprepared beforehand by reacting cupric chloride with triphenylphosphinepossesses time a stable capability for a longer period of in comparisonwith Catalyst A7 which carried firstly copper chloride and thentriphenylphosphine.

EXAMPLE 7

Into an autoclave were charged 50 ml of methanol, 0.07 mol of oxygen,0.149 mol of carbon monoxide, 0.078 mol of N₂ and 0.01 mol (3.61 g) of acomplex (Catalyst A10) represented by the formula Cu(PPh₃)Cl, and areaction was conducted under agitation for 6.5 hours under liquid phasereaction conditions of 13 kg/cm2G and 120° C. to obtain a DMC formationrate of 5.05 mol/1-MeOH g·mol complex·h.

On the other hand, a reaction was conducted in the same manner with theabove using 0.01 mol (1.344 g) of a conventional CuCl₂ catalyst toobtain a DMC formation rate of 2.5 ml-1/1-MeOH·g-mol catalyst·h. Fromthese results, it is noticed that Catalyst A10 is two times as active asCuCl₂.

EXAMPLE 8

The complex Cu(PPh3)Cl prepared in Example 7 was carried on an activecarbon (surface area: 1000 m² /g; 4.16 mesh) to prepare a catalyst (Cucontent 3 wt.%), and 10 grams of the catalyst was used to conduct areaction under the same conditions with Example 7. The amount of complexcarried on the catalyst was 0.004 mol (1.46 g). As the result, a DMCformation rate of 24.2 mol/1.MeOH·g-mol complex·h was obtained, whichwas about 5 times of the case of Example 7 using singly a complexCu(PPh₃)Cl.

EXAMPLE 9

Under the same reaction conditions with Example 7, a reaction wasconducted using 0.01 mol (6.23 g) of Catalyst A20 [Cu(PPh₃)₂ Cl: nocarrier]. As the result, a DMC formation rate of 1.03 mol/1-MeOH·g-molcomplex·h was obtained.

EXAMPLE 10

Under the same reaction conditions with Example 7, a reaction wasconducted using 10 grams of Catalyst A22 [Cu(PPh₃)₂ Cl; carried onactive carbon]. The amount of complex carried on the catalyst was 0.0036mol (2.27 g). As the result, a DMC formation rate of 7.20mol/1-MeOH·g-mol complex·h was obtained, which was about 7 times of thecase of Example 9 using Catalyst A 20 [Cu(PPh₃)₂ Cl; no carrier].

EXAMPLE 11

Under the same reaction conditions with Example 7, a reaction wasconducted using 0.01 mol (9.30 g) of Catalyst A33 [Cu(PPh₃)₃ Br; nocarrier]. As the result, a DMC formation rate of 0.85 mol/1-MeOH·g·molcomplex·h was obtained.

EXAMPLE 12

Under the same reaction conditions with Example 7, a reaction wasconducted using 10 grams of Catalyst A34 [Cu(PPh3)3 Br; carried onactive carbon]. The amount of complex carried on the catalyst was 0.0033mol (3.05 g). As the result, a DMC formation rate of 5.10mol/1-MeOH·g-mol complex·h was obtained, which was 6 times of the caseof Example 11 using Catalyst A33 [Cu(PPh₃)₃ Br; no carrier].

EXAMPLE 13

Under the same reaction conditions with Example 7, a reaction wasconducted using 0.01 mol (4.06 g) of Catalyst A27 [Cu(PPh₃)Br;nocarrier]. As the result, a DMC formation rate of 5.28 mol/1-MeOH·g-molcomplex·h was obtained.

EXAMPLE 14

Under the same reaction conditions with Example 7, a reaction wasconducted using 10 grams of Catalyst A28 [Cu(PPh₃)Br; carried on activecarbon](Cu content 3 wt.%). The amount of complex carried on thecatalyst was 0.004 mol (1.61 g). As the result, a DMC formation rate of31.9 mol/1-MeOH·g-mol complex·h was obtained, which was about 6 times ofthe case of Example 13 using Catalyst A27 [Cu(PPh₃)Br; no carrier].

It is noticed that a copper complex comprising a copper halide and atertiary organophosphorus compound is effective for the liquid phaseproduction of carbonic acid esters, and especially that a complexcarried on a porous carrier is remarkably active.

INDUSTRIAL APPLICATION

It is possible to produce carbonic acid esters effectively.

We claim:
 1. A method of producing carbonic acid esters by reacting analcohol with carbon monoxide and oxygen in the presence of a catalyst,the catalyst comprising one of:(a) a copper halide and a tertiaryorganophosphorus compound in a ratio of 0.05-0.4 mol of the tertiaryorganophosphorus compound per copper atom mol in the copper halide, thetertiary organophosphorus compound having a phenyl group or an alkylgroup, and the copper halide and the tertiary organophosphorus compoundbeing carried on a porous carrier; and (b) a copper complex having amolar ratio copper atom: the tertiary organophosphorus compound: halogenatom of 1:1-3: 1 prepared by reacting the copper halide with thetertiary organophosphorus compound, and the copper complex being carriedon a porous carrier.
 2. A method of producing carbonic acid estersaccording to claim 1, wherein the tertiary organophosphorus compound isselected from the group consisting of triphenylphosphine,triphenylphosphite, dimethylphenylphospine, trimethylphosphite,triethylphosphite, triethylphosphate and trimethylphosphate.
 3. A methodof producing carbonic acid esters according to claim 1, wherein theamount of copper in the catalyst is 2-10 wt. % per carrier.
 4. A methodof producing carbonic acid esters according to claim 1, wherein theporous carrier is selected from the group consisting of active carbon,titanium oxide, zirconium oxide, niobium oxide, magnesium oxide, silicaand alumina.
 5. A method of producing carbonic acid esters according toclaim 1, wherein the alcohol is selected from the group consisting ofaliphatic alcohols having 1-4 carbon atoms, alicyclic alcohols andaromatic alcohols.
 6. A method of producing carbonic acid estersaccording to claim 1, wherein the method is carried out undertemperatures of 70°-200° C. and pressures of 0-30 kg/cm² G.
 7. A methodof producing carbonic acid esters according to claim 1, in which thecopper complex is represented by a formula Cu(PPh₃)_(n) X, wherein PPh₃is P(C₆ H₅)₃ ; X is a halogen and n is 1, 2 or
 3. 8. A method ofproducing dimethyl carbonate by reacting methanol with carbon monoxideand oxygen in the presence of a catalyst in a vapor phase under areaction temperature of 70°-200° C. and a reaction pressure of fromatmospheric pressure to 15 kg/cm² G, the catalyst comprising one of:(a)a copper halide and a tertiary organophosphorus compound in a ratio of0.05-0.4 mol of the tertiary organophosphorus compound per copper atommol in the copper halide, the tertiary organophosphorus compound havinga phenyl group or an alkyl group, and the copper halide and the tertiaryorganophosphorus compound being carried on a porous carrier; and (b) acopper complex having a molar ratio copper atom: tertiaryorganophosphorus compound: halogen atom of 1:1-3:1 prepared by reactinga copper halide with the tertiary organophosphorus compound, the coppercomplex being carried on a porous carrier.
 9. A method of producingdimethyl carbonate according to claim 8, wherein the tertiaryorganophosphorus compound is selected from the group consisting oftriphenylphosphine, triphenylphosphite, dimethylphenylphosphine,trimethylphosphite, triethylphosphite, triethylphosphate andtrimethylphosphate.
 10. A method of producing dimethyl carbonateaccording to claim 8, wherein the amount of copper in the catalyst is2-10 wt. % per carrier.
 11. A method of producing dimethyl carbonateaccording to claim 8, wherein the porous carrier is selected from thegroup consisting of active carbon, titanium oxide, zirconium oxide,niobium oxide, magnesium oxide, silica and alumina.
 12. A method ofproducing dimethyl carbonate according to claim 8, wherein the molarratio of carbon monoxide to methanol is 1:1.2-0.5 and the molar ratio ofoxygen to carbon monoxide is 1:0.55-0.01.
 13. A method of producingdimethyl carbonate according to claim 8, in which the copper complex isrepresented by a formula Cu(PPh₃)_(n) X, wherein PPh₃ is P(C₆ H₅)₃ ; Xis a halogen and n is 1, 2 or
 3. 14. A method of producing dimethylcarbonate by reacting methanol with carbon monoxide and oxygen in thepresence of a catalyst in a liquid phase under a reaction temperature of80°-150° C. and a reaction pressure of 5-30 kg/cm² G, the catalystcomprising one of:(a) a copper halide and a tertiary organophosphoruscompound in a ratio of 0.05-0.4 mol of the tertiary organosphosphoruscompound per copper atom mol in the copper halide, the tertiaryorganophosphorus compound having a phenyl group or an alkyl group, andthe copper halide and the tertiary organophosphorus compound are carriedon a porous carrier; and (b) a copper complex having a molar ratiocopper atom: the tertiary organophosphorus compound: halogen atom of1:1-3:1 prepared by reacting the copper halide with the tertiaryorganophosphorus compound, the copper complex being carried on a porouscarrier.
 15. A method of producing dimethyl carbonate according to claim14, wherein the tertiary organophosphorus compound is selected from thegroup consisting of triphenylphosphine, triphenylphosphite,dimethylphenylphosphine, trimethylphosphite, triethylphosphite,triethylphosphate and trimethylphosphate.
 16. A method of producingdimethyl carbonate according to claim 14, wherein the amount of copperin the catalyst is 2-10 wt. % per carrier.
 17. A method of producingdimethyl carbonate according to claim 14, wherein the porous carrier isselected from the group consisting of active carbon, titanium oxide,zirconium oxide, niobium oxide, magnesium oxide, silica and alumina. 18.A method of producing dimethyl carbonate according to claim 14, whereinthe molar ratio of carbon monoxide to methanol is 1:1.2-0.5 and themolar ratio of oxygen to carbon monoxide is 1:0.55-0.01.
 19. A method ofproducing dimethyl carbonate according to claim 14, in which the coppercomplex is represented by a formula Cu(PPh₃)_(n) X, wherein PPh₃ is P(C₆H₅)₃ ; X is a halogen and n is 1, 2 or 3.